Why is it helpful to estimate the answer before adding or subtracting decimals?

1 answer:

7 0

<span>Being able to estimate your answer is a very useful skill. ... When decimals are involved, it's very easy to put the decimal point in the wrong place, and ... round all numbers to the same place value—this makes adding or subtracting a bit easier.</span>

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a pyramid has a regular hexagonal base with side length of 4 and a slant height of 6. what is the total area of the pyramid

Stels [109]

So hmm notice the picture below

the pyramid itself, is really, just one regular hexagon, at the bottom
and 6 triangles, stacked up at each other at the edges

now, if you just get the area of the regular hexagon, and the 6 triangles, add them up, that'd be the total surface area of the pyramid then
$\bf \textit{area of a regular polygon}\\\\
A=\cfrac{1}{4}\cdot n\cdot s^2\cdot cot\left( \frac{180}{n} \right)\qquad 
\begin{cases}
n=\textit{number of sides}\\
s=\textit{length of a side}\\
\frac{180}{n}=\textit{angle in degrees}\\
----------\\
n=6\\
s=4
\end{cases}\\\\\\ A=\cfrac{1}{4}\cdot 6\cdot 4^2\cdot cot\left( \frac{180}{6} \right)$

now, for the triangles, well, area of a triangle is 1/2 bh, as you'd know, and you have both

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3 years ago

Help please and thank u

Damm [24]

Answer:

Point S is your answer.

Step-by-step explanation:

See how all of them are rays, but they all connect at point S.

Point S is your answer.

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3 years ago

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Jacky read at the rate of 15 pages per hour. Johnny read at the rate of 1/3 of a pages per minute. Who was reading faster? By ho

o-na [289]

We can compare by converting Johnny's reading time into the same unit of Jacky's, hours.

There are 60 minutes in an hour, so use this:

$\frac{1}{3} * \frac{60}{1} = 20$

15 < 20, so Johnny read faster. This is 5 pages faster per hour than Jacky.

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3 years ago

How to find the points of a line that is perpendicular to a line you only know the slope of

Lady bird [3.3K]

Answer:

Write the new equation in slope-intercept form. Replace the old slope with the new slope. Replace the y-intercept's value with a variable (b).

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3 years ago

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Emily's younger brother, Kenny, begged her to make him a superhero costume for Halloween this year, so of course Emily did! Emil

iris [78.8K]

Answer:

20 inches

Step-by-step explanation:

Since the cape is trapezoid shaped and has an area of 600 in², the area of a trapezoid is given by

A =1/2(a + b)h where a = length along the top of the cape = 24 in, b = length along the bottom of the cape = 36 in and h = height of the cape

So, h = 2A/(a + b)

= 2 × 600 in²/(24 in + 36 in)

= 1200 in²/60 in

= 20 in

So, the height of the cape is 20 inches

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2 years ago